Flight Deck Computer Harness, Which One to Buy?

I have 9 speed, Flight Deck compatible, 105 STI shifters. I like the idea of going with a FlightDeck computer, but I'm not sure which harness to buy. I'm looking on ebay and want to be sure I buy the right one. My shifters are model ST-5510, there is no "c" after the numbers. It is a 9 speed, triple set up.
Can I use any of the 9 speed harnesses for these shifters or are there specific harnesses that work with these units and others won't? I'm just plain ignorant when it comes to Flight Deck.
Thanks for all help.

I have 105's with a Flight Deck. I looked for numbers on both the sensor and the shifters, but did not find anything. This link is to the same book that came with the computer. There is a table near the front that may help. I suspect that the SM 6501 will work. The others are for Mountain bike type shifters. Hopefully, it will help. You can also check out their tech sheeets by going to: http://techdocs.shimano.com/techdocs/index.jsp